1. Trading Chad Pennington is not only risky, he’d rather be a backup in Miami than a starter elsewhere: Ever since Brett Favre kinda-sorta-but-not-quite-yet retired on Tuesday afternoon, it’s been hard not to notice that the Dolphins have four quarterbacks on their roster, three of which you could envision taking game snaps this regular season.

Surely, the Dolphins won’t keep four quarterbacks on their roster this season. And surely, Dolphins GM Jeff Ireland realizes he can trade one of his quarterbacks for a future draft pick. It’s not a terrible idea – a local columnist fully endorses trading Pennington in today’s newspaper – but there are a few reasons why the Dolphins should hold off.

“First of all, we don’t know if he’s going to retire,” Pennington quipped on Wednesday.

The Dolphins can probably get a draft pick for Chad Pennington, but is it worth it? / AP

But it’s also a risky move that would hurt Miami’s quarterback depth. The team has Super Bowl aspirations this year, and if Chad Henne goes down, are the Dolphins really going to hand the keys to the Porsche over to Tyler Thigpen, a fourth-year pro who never had a quarterback coach until he came to Miami last year and has a career passer rating of 73.8?

While Tony Sparano has said he hasn’t determined his backup quarterback, the bet here is the smart, veteran Pennington would get the call over the talented but young Thigpen. Certainly no offense to Thigpen, but he simply can’t match the experience and pedigree that Pennington, when healthy, brings to the position. And Thigpen, eight years younger than Pennington and with a healthier shoulder, may even have more trade value, anyway.

Then there’s this: Pennington is really happy in Miami. He doesn’t mind backing up Henne. He is a great mentor for the younger players on the team. He wanted a no-trade clause in his contract this offseason, but instead will get a $1.5 million bonus if he is traded.

I asked Pennington specifically about the Vikings on Wednesday, and why would he rather be a backup in Miami than a starter elsewhere?

“I really enjoy who I work for and who I work with, and I think that’s important as you become a veteran in this league,” Pennington said. “I have a role and a niche here, and I understand our staff and our staff understands me. The way we play offense, the way Tony wants us to play as a quarterback, that’s me. He appreciates those little things that quarterbacks do that aren’t in the stat sheet.”

“But at the same time, I understand the league and I understand the possibilities of what could happen. So like I said in the spring, I’m prepared to get cut and I’m prepared to start 16 games, and everything in between.”

Unless the Vikings – or another team desperate for a quarterback, like, say, the Bills — offer a second- or third-round draft pick for Pennington (which I don’t see happening, given Pennington’s injury history and advancing age), the Dolphins would be best served by keeping him around.

2. Tony Sparano better be careful with his veterans for the rest of camp: So far, the Dolphins have avoided catastrophe. Rookie A.J. Edds was lost to a torn ACL and second-year running back Kory Sheets to a torn Achilles, but no key players have suffered an injury in training camp – yet.

This may be the only photo that exists of Kory Sheets in a Dolphins uniform / Sun-Sentinel

The Dolphins’ practice bubble went silent Wednesday evening when Brandon Marshall twisted his ankle and crumpled to the turf while making a cut in a 1-on-1 Red Zone drill. Marshall popped back up and was fine, but the Dolphins’ grand plans were almost ruined in an instant.

Marshall, Ronnie Brown, Karlos Dansby and several other veterans have nothing to prove this camp. Sparano might want to consider sitting them on the sidelines more to avoid a catastrophic injury, and also allow the younger guys to get more reps.

3. The beat goes on in kick returner competition: Sheets was no lock to make the 53-man roster, but Sparano sure wanted Sheets, perhaps the team’s best home-run hitter, to stand-out on kickoff returns during the preseason.

Now with his right Achilles torn — without being touched by a defender, no less — the Dolphins now must turn to Patrick Cobbs (22.6 average on 16 kicks in 2009), Brian Hartline, Nolan Carroll,Julius Pruitt or Taurus Johnson to replace the departed Ted Ginn Jr. Cobbs and Hartline are the likely front-runners, though Carroll, a rookie fifth-rounder, has impressed as both a cornerback and returner.

Sheets’ injury also means third-year running back Lex Hilliard almost certainly has a spot on the 53-man roster as a fourth running back and special teamer.